Commodities and Projects

The Georgia Pest Management Handbook

The thirty-first edition of the Georgia Pest Management Handbook gives current information on selection, application, and safe use of pest control chemicals. The Handbook has recommendations for pest control on farms, around homes, urban areas, recreational areas, and other environments in which pests may occur. Cultural, biological, physical, and other types of control are recommended where appropriate. Commercial and Homeowner editions are available.

Blueberries

The blueberry industry in Georgia is expected to grow to more than $90 million by 2014. Returns of up to $18,000/acre have been realized with the earlier maturing southern highbush blueberry cultivars. Xylella fastidiosa, bacterial leaf scorch of blueberry, was initially observed ca. 2004. X. fastidiosa has numerous strains which vary from asymptomatic to highly virulent pathogens that can debilitate or kill host plants in as few as three growing seasons. In other host plants X. fastidiosa has always been shown to be insect-vectored, in most cases by select leafhopper species. Currently, information is lacking on X. fastidiosa epidemiology in Georgia blueberries.

The blueberry team will work to identify the species composition and seasonal distribution of leafhopper species feeding on blueberries in order to better define X. fastidiosa transmission throughout the growing season. This will impact grower management strategies for the coming growing seasons. As leafhopper population dynamics and X. fastidiosa transmission become better understood, targeted management strategies will be refined, reducing the number of required insecticide applications. Ultimately, refined management strategies for leafhoppers and X. fastidiosa will be included in an overall pest management strategic plan for blueberries. Improving management of these pests will improve profitability for the producer and reduce health and environmental risks by reducing the number of insecticide applications.

Cotton

Georgia currently ranks second in the U.S. in bale production and planted cotton acreage (5 year averages are 1.9 million bales produced on 1.1 million acres). Increased management and use of IPM programs has replaced numerous insecticide applications resulting in increased profits for growers, a more sustainable production system, and an improved environmental profile.

Dramatic changes in cotton pest management have transformed the production system, and acreage has increased nearly ten-fold since 1983. Elimination of the boll weevil and adoption of Bt transgenic varieties allowed producers to utilize natural controls more effectively and implement much improved IPM programs. Annual insecticide applications have been reduced from more than 15 during the early 1980s to less than five (5 yr average is 2.6). However, the complex of key pests has changed in the reduced insecticide use production environment. Currently, stink bugs are a primary pest of cotton in Georgia and the southeast. Knowledge of basic stink bug biology and ecology in cotton and the farmscape has improved in recent years. This information will be used to refine thresholds, improve sampling, and develop innovative management programs such as in-field border applications of insecticides where only a portion of the field is treated. Cotton continues to be an intensively managed crop.

Peaches

Fungicide resistance monitoring and brown rot disease management for peach production in Georgia and South Carolina

Peaches are the most important tree fruit industry in the southeastern United States. The majority of production is concentrated in South Carolina (5,868 bearing hectares) and Georgia (4,856 hectares), and the value of the total utilized peach production in both states combined was estimated to exceed $69 million in 2008. The humid, warm southeastern climate is conducive for fungal and bacterial disease development and epidemics. In any given year, brown rot, caused by Monilinia fructicola, can cause substantial damage ($9.8 million est. 2003) on peach fruit.

Although an integrated approach is currently being used to control brown rot, including sanitation practices and cultural methods, management still depends heavily on two or three fungicide applications prior to harvest. Over the past 25 years or so, these applications have relied primarily on fungicides within a single class – the demethylation inhibitors (DMIs), but more recently, spray programs have shifted to rotations of respiration inhibitors (RIs) with DMIs. There is now extensive resistance to the DMIs in many locations, and if resistance to RIs were to increase, there would be a catastrophic control failure with the current system. Producers must know that a resistance shift has occurred if they are to adjust their spray programs to other chemical classes (i.e. benzimidazoles) to manage the disease effectively.

This project has developed a fungicide resistance monitoring program that has recently been implemented in the peach growing region of Georgia. For more information on this project, please see the 2009 report (PDF file) or visit www.peachdoc.com.

Peanuts

Georgia produces about 40% of the U.S. supply of peanuts, with annual yields from 2000-2008 ranging from 1.3 billion – 3.4 billion pounds. Peanut pests are many and varied and often vary from year to year. The most important problems in recent years were diseases and thrips species that vector tomato spotted wilt virus (TSWV), and lepidopterous defoliators in early season.

Peanuts are an ideal crop for IPM. Host plant resistance has great potential to reduce pesticide inputs and increase peanut profitability. Recent released cultivars have moderate to high levels of resistance and/or tolerance to leaf spot pathogens. The use of partial resistance to the leaf spot pathogens represents a means for significantly reducing the amount of fungicides required for peanut production. Further, the use of a resistant cultivar is the single most important factor in control of TSWV. A "risk assessment index", developed by the Peanut Team, has been a very valuable tool for helping growers and advisors make decisions that reduced risk for a given farm and situation. For more information on Peanut Team activities, please visit the 2009 Peanut Update report, or go to http://ugapeanuts.com/.

Vegetables

The Vegetable IPM Program in Georgia is very diverse, with educational and research activities addressing over 30 commercially produced vegetable crops within the state. The diversity of the vegetables produced and the multiple production seasons in Georgia make vegetable IPM particularly challenging. A single crop produced in the spring versus the fall frequently has very different pest problems.

IPM in vegetables relies on multiple tactics, which vary greatly among crops. Plasticulture plays a major role in weed and disease suppression in some of the more valuable crops (i.e. tomato, pepper, eggplant); host plant resistance is a critical component in virus suppression (i.e tomato spotted wilt, mosaic viruses of squash); and avoidance (spring production) plays a key role in caterpillar management in sweet corn. However, pesticides are essential for pest management in commercial vegetable production.

The necessity for efficacious pesticides provides two challenges for IPM in Georgia vegetables: 1) integration of new, more environmentally friendly, chemistries into current management programs and 2) management of pesticide resistance. New pesticides are continually developed and introduced. Most of these chemistries are more environmentally friendly, but they are more selective and more expensive. Often, unique application methodology or timing is required for new pesticides to be effective. Proper integration of these products into IPM programs requires a thorough understanding of the production system, the pest potential, and product performance.